Linux Kernel in a Nutshell (In a Nutshell (O'Reilly))
Written by a leading developer and maintainer of the Linux kernel,Linux Kernel in a Nutshell is a comprehensiveoverview of kernel configuration and building, a critical task forLinux users and administrators.
No distribution can provide a Linux kernel that meets all users'needs. Computers big and small have special requirements that requirereconfiguring and rebuilding the kernel. Whether you are trying toget sound, wireless support, and power management working on a laptopor incorporating enterprise features such as logical volume managementon a large server, you can benefit from the insights in this book.
Linux Kernel in a Nutshell covers the entirerange of kernel tasks, starting with downloading the source and makingsure that the kernel is in sync with the versions of the tools youneed. In addition to configuration and installation steps, the bookoffers reference material and discussions of related topics such ascontrol of kernel options at runtime.
A key benefit of the book is a chapter on determining exactly what drivers are needed for your hardware. Also included are recipes thatlist what you need to do to accomplish a wide range of popular tasks.
number of the new kernel you just installed. The label does not matter, so long as it is unique, but it is displayed in the boot menu, so you should make it something meaningful. In our example, we installed the 18.104.22.168 kernel, so the final copy of the file looks like: boot=/dev/hda prompt timeout=50 default=2.6.12 image=/boot/bzImage-2.6.15 label=2.6.15 read-only root=/dev/hda2 image=/boot/bzImage-2.6.12 label=2.6.12 read-only root=/dev/hda2 image=/boot/bzImage-2.6.17 label=2.6.17
to configure the kernel. Run the menu configuration tool: $ make menuconfig Then press the / key (which initiates a search) and type in the configuration option, minus the CONFIG_ portion of the string. This process is shown in Figure 7-1. Figure 7-1. Searching in menuconfig The kernel configuration system will then tell you exactly where to select the option to enable this module. See Figure 7-2. Figure 7-2. Result of searching in menuconfig The first item in the display
that should be taken care of. 5 (KERN_NOTICE) Normal, but significant events. 6 (KERN_INFO) Informational messages that require no action. 7 (KERN_DEBUG) Kernel debugging messages, output by the kernel if the developer enabled debugging at compile time. Name log_buf_len — Set the size of the kernel log buffer. Synopsis log_buf_len= n[KMG] Set the size of the kernel's internal log buffer. n must be a power of 2, if not, it will be rounded up to be a power of two.
that go from that host to you) or if you operate a non-routing host that has several IP addresses on different interfaces. To turn rp_filter off, enter: echo 0 > /proc/sys/net/ipv4/conf/device/rp_filter or echo 0 > /proc/sys/net/ipv4/conf/all/rp_filter Name NETFILTER — Network packet filtering Netfilter is a framework for filtering and mangling network packets that pass through your Linux box. The most common use of packet filtering is to run your Linux box as a firewall
serial port for anything. In addition, the Cyclades and Stallion multi serial port drivers do not need this driver. Note Do not compile this driver as a module if you are using non-standard serial ports, because the configuration information will be lost when the driver is unloaded. This limitation may be lifted in the future. Most people will say yes here, so that they can use serial mice, modems, and similar devices connected to the standard serial ports. Name AGP —